In this biography of jazz pianist Mary Lou Williams, sisters Ingalls (a newcomer) and Macdonald (Copycat Costume) record the trials of an African-American child who migrates from Atlanta to Pittsburgh , and the joy music offers her. Life in Pittsburgh is hard: neighbors throw bricks through their windows, and Mary has to borrow her mother’s too-small shoes for the first day of school. “Ugly names and cruel words… Mary called them ‘bad sounds,’ and she taught herself to play them out.” Her family and friends recognize and appreciate her gifts, though, and Mary soon witnesses the effects of her music. “When Mary cut loose, people couldn’t stay still…. Her blue notes made people want to cry at just how hard life can be. Her crazy chords made people shimmy their shoulders and shake their heads.” Potter’s (The Boy Who Loved Words) folk art–style gouache paintings provide a vivid portrait of industrial Pittsburgh at the beginning of the 20th century, yet have an iconic quality, too. Ingalls and Macdonald provide a touching memorial to a jazz great who is not a household name—a valuable contribution. Ages 6–9. (Jan.)